EP3082002B1 - Safety control and method for controlling an automated system - Google Patents

Description

The present invention relates to a safety controller and a method for controlling an automated system as a function of project data according to the preambles of claims 1 and 11, the project data representing an application running on the system.

A safety controller in the sense of the present invention is a device or a device that receives input signals supplied by sensors and generates output signals therefrom by means of logic operations and possibly further signal or data processing steps. The output signals can then be fed to actuators which, depending on the input signals, cause actions or reactions in a controlled system.

A preferred area of application for such safety controls is the monitoring of emergency stop buttons, two-hand controls, protective doors or light grids in the field of machine safety. Such sensors are used, for example, to secure a machine that poses a risk to people or material goods during operation. When the protective door is opened or the emergency stop button is pressed, a signal is generated that is fed to the safety control as an input signal. In response to this, the safety control then switches off the dangerous part of the machine, for example with the help of an actuator.

A characteristic of a safety controller, in contrast to a "normal" controller, is that the safety controller always guarantees a safe state of the hazardous systems or machines even if a malfunction occurs with it or one of the devices connected to it. For this reason, extremely high demands are placed on safety controls for their own fault tolerance, which results in considerable effort in development and manufacture.

As a rule, safety controls require special approval from the competent supervisory authorities before they can be used, such as in Germany from the employers' liability insurance association or the TÜV. The safety controller must comply with specified safety standards, which are laid down, for example, in the European standard EN 954-1 or a comparable standard, for example the standard IEC 61508 or the standard EN ISO 13849-1. In the following, therefore, a safety controller is understood to mean a device or a device that meets at least safety category 3 of the mentioned European standard EN 954-1 or whose Safety Integrity Level (SIL) reaches at least level 2 according to the mentioned standard IEC 61508.

A programmable safety control offers the user the possibility of individually defining the logical links and, if necessary, further signal or data processing steps with the help of software, the so-called user program, according to his needs. This results in a Great flexibility compared to previous solutions in which the logical links were created through defined wiring between different safety modules. A user program can be created, for example, with the aid of a commercially available personal computer (PC) and using appropriately set up software programs. The term user program is understood to mean that a user program includes both source code and machine code.

In the case of large and thus complex systems according to the state of the art, which are built up from a large number of system hardware components, distributed safety controls are usually used. Distributed safety controls consist of a large number of control hardware components. These are control units, sensors and actuators. The individual control hardware components are assigned to individual system hardware components. With regard to the hardware, distributed safety controls are characterized by great flexibility. A safety controller can be built from any number of different control hardware components and can therefore be adapted very flexibly to the conditions of the system to be controlled. With regard to the programming or software implementation and thus the issues of data processing, however, distributed safety controls are not yet optimal. There is no provision for distributing project data, that is, data that represent an application running on the controlled system, to the individual control hardware components. This not only limits the flexibility that is possible with regard to the hardware implementation to a considerable extent, it also entails further disadvantages. Because the project data cannot be distributed and thus processed "on site", a not inconsiderable exchange of data between control hardware components, some of which are far away, is necessary. This leads to an impairment, more precisely to an increase in the response time of the safety controller. "On site" in this context means that the project data is processed where the data required for its processing is available. For example, in a control unit that is located in the immediate vicinity of a sensor, whose sensor signal is required as an input signal for determining a control signal for an actuator. Or processing even takes place in the sensor itself. Instead, appropriately designed control hardware components and data buses are used to avoid impairment of the response time, which allow a higher exchange of data than would actually be necessary. This increases the cost of implementing a safety controller. Another disadvantage with regard to costs is that in individual control hardware components, in particular in intelligent sensors and intelligent actuators, any available free memory, more precisely data memory, is not used and instead the data memory contained in control units has to be dimensioned larger than is actually necessary were.

US 6,170,044 B1 discloses a system and a method according to the preambles of claims 1 and 11. The system includes a plurality of process controls, each of which controls a sub-process in a plant. A higher-level controller communicates with the process controllers and generates higher-level data in order to optimize the process flow in the plant. At least some of the process controls are redundant, with a first processor module controlling a partial process, while a second processor module remains passive until the first processor module fails and its control tasks are taken over by the second processor module. In order to achieve a seamless transition, process data in the memory of the second processor module are continuously synchronized with the process data in the memory of the first processor module.

U.S. 5,699,242 discloses a control system for a factory plant with a plurality of control devices. So-called end control devices, for example in the form of programmable logic controllers (PLC), control individual sub-processes. Groups of end control devices are coordinated by higher-level controls. Several end control devices can use a common memory area in order to carry out functionally identical tasks.

EP 1 231 526 A1 discloses a control system with a plurality of networked controllers. A so-called connection memory stores process data in the Network to be shared. The individual controls use uniform variable names to access this shared data.

It is an object of the present invention to develop a safety controller and a method of the type mentioned at the outset in order to reduce the costs for the implementation of a safety controller and to enable a more flexible safety controller that is optimized in terms of availability.

This object is achieved by a safety controller and a method according to claims 1 and 11.

The new safety control and the new method are based on the idea of providing a distribution unit in a safety control that is designed to distribute at least part of the project data to data memories contained in control hardware components and thus the distribution of project data to control hardware components that make up the safety control is to enable. In this way, project data can be specifically saved in individual data memories that are contained in various control hardware components. This also enables project data to be saved in so-called intelligent input / output units. These are sensors and actuators that have data processing units, for example microprocessors, and data memories. As a result, data memories available in a safety controller, which would otherwise largely remain unused, can be filled with project data and thus used. As a result, control units that are present in a safety controller can be equipped with smaller data memories in the future. This reduces the costs for a safety controller.

At the same time, the response time of a safety controller is reduced. Project data can be saved there and are therefore available where, for example, required sensor signals are present or control signals for actuators are to be provided. This reduces the data exchange, which ultimately leads to a reduction in the response time. The reduction in data exchange also leads to an increase the availability of the safety controller. Since there is less data to be exchanged, there are also fewer data transmission errors.

Distributing and thus saving project data in several project data memories also has advantages with regard to the implementation and handling of a safety controller. If, for example, after planning a safety controller in trial operation, it is found that the memory capacity available in the safety controller and formed by all data memories is too small, this can be increased by adding an additional control hardware component that has a data memory. The project data can then be redistributed to the previous and additional data memories. The safety controller can therefore be scaled as required.

If the data memory contained in a control hardware component is also designed, for example, as a removable memory card, the project data required for the new control hardware component can be provided in a simple manner if a device replacement is necessary. All that is required is to remove the memory card from the defective control hardware component to be removed and insert it into the new control hardware component to be inserted. Thus, for example, address data, configuration data and program data can be made available without a notebook having to be connected to the new control hardware component for this purpose.

The project data include program data and / or configuration data and / or parameterization data.

The program data represent the user program and are generated when the user program is created. The configuration data represent individual aspects of the data transmission. This involves, for example, a cycle time, link data that determine which of the control hardware components are connected to one another, or data that represent which sensors or actuators, which inputs or outputs of individual control units are assigned, or to data that determine the type of data to be exchanged between individual control hardware components, for example. It is therefore data that represent the configuration of the safety control that is implemented in a distributed manner. The configuration data can be generated when creating the user program. However, they can also be created or changed to a certain extent after the user program has been created. The parameterization data represent value ranges for individual variables or functionalities used in the user program. These data can be specified when the user program is created or can be created at a later point in time. This measure enables a particularly effective optimization of the safety control in terms of computing power or response time. In this way, program data can be saved where they are processed. Configuration data and parameterization data can be stored where those units are installed for which they are intended.

At least some of the control hardware components contain a data processing unit, project data specific to the respective data processing unit being stored in that project data memory that is contained in that control hardware component in which the data processing unit is contained.

This principle of local data storage, in which the project data is stored where it is processed, enables fast and particularly effective processing of control tasks and thus a reduction in the response time of a safety controller. A data processing unit can be a unit to which data is supplied as input data for an operation and which outputs output data determined as a result of this operation as a function of the input data. A data processing unit can, however, also be understood to mean a unit to which data is supplied in order to pass it on to another unit. Safety controls contain data processing units in the most varied of configurations. For example, data-based message switching units are used. For example, these make data generated by their own control unit available to other control units and read data generated by other control units, which are required in the own control unit for further processing. Such data processing units are known as data brokers. Event-based message switching units can also be involved. Such message switching units send a signal when a defined condition is met in their own control unit in order to trigger a defined reaction in another control unit or in the system to be controlled. Such message switching units also receive such signals in a corresponding manner. Such message switching units are known as event brokers. In addition, connection units are also used that are required to enable data exchange between individual control hardware components at all. Such data processing units are referred to as data bus interfaces. In addition, a project data memory is also a data processing unit, since the project data memory can not only store project data but also request and forward project data. Depending on how the data processing unit is designed, the respective project data stored for the data processing unit differ. For a data broker, an event broker or a data bus interface, for example, configuration data and parameterization data are stored. In addition to parameterization data and configuration data, project data are also stored for a project data memory, preferably those project data that are processed in the control unit in which the project data memory is contained.

At least one of the project data memories is designed to forward project data supplied to it to at least one other project data memory or to request project data stored in another project data memory.

This measure enables a flexible distribution of the project data to the project data memory contained in a safety controller. Because one of the project data memories is designed to forward project data, it can be used to distribute the project data to the project data memories arranged in a safety controller. Because at least one of the project data memories is designed to request project data from another project data memory, it is not absolutely necessary that the data in a control hardware component to save the required project data on the project data memory that is arranged in this component. Instead, it is possible to save this project data in any project data memory, as this can be requested at any time. At least one of the project data memories is advantageously equipped with both functional features, ie designed to both forward project data and request project data. This enables a particularly flexible distribution of the project data. A project data memory, which is designed to store, forward and request project data, can also be referred to as a project data server, or project server for short, due to this range of functions. In a further embodiment, the distribution unit is one of the project data memories.

This measure has the advantage that no additional unit needs to be provided in the safety controller for distributing the project data. The project data is distributed from one of the project data memories already present in the safety controller. This enables a cost-effective implementation of the safety control. Another advantage is that functionalities that are present in a project data memory and that have been optimized with regard to the processing of project data can be used for distributing the project data. The interface of a project data memory is given as an example. The project data memory that is used as a distribution unit has the function of a master when distributing the project data. The remaining project data memories each take on the function of a slave. The project data memory that is used as a distribution unit advantageously has a greater storage capacity than would be required for the operation of that control hardware component in which it is arranged. For the following reason: When the project data is distributed, data is generated that is required for later operation of the safety controller. These can thus be cached in the aforementioned project data memory.

The project data are usually created using a programming tool that runs on a programming unit. This is usually a structurally separate unit from the safety controller. The programming unit comprises, for example, a computer designed as a personal computer. For the transfer Several alternatives are conceivable for transferring the project data from the programming unit to the project data memory that is used as a distribution unit. For example, the programming unit can be connected via a cable to that control hardware component in which the project data memory is contained, or even to the project data memory itself. This configuration is particularly suitable when the complete project data is to be imported into the safety controller in a single process. In a further embodiment, the project data can be transferred to the project data memory using a mobile storage medium. As a mobile storage medium, for example, memory cards, which can be designed as SD cards (Secure Digital Memory Cards) or CF cards (Compact Flash Cards), or a USB stick (Universal Serial Bus) can be used. When using a mobile storage medium, a conscious user action is advantageously to be carried out for the initialization of the distribution process. For example, on the control hardware component into which the mobile storage medium is inserted, a specific key combination has to be pressed or a button has to be pressed or a defined input has to be made via a graphic surface. With the direct transfer of the project data from the programming unit to the project data memory, the distribution process is advantageously initialized automatically by the programming unit.

The use of a mobile storage medium has various advantages. It is thus possible to only upload project data to selected control hardware components by specifically connecting the mobile storage medium to these control hardware components. Another advantage is that the mobile storage medium can also be used for backup purposes. The machine code stored in a safety controller can be stored on the mobile storage medium and read into the safety controller again if necessary.

In a further embodiment of the invention, the distribution unit is an external distribution unit which is connected at least temporarily to an interface provided for this purpose in the safety controller.

It is particularly advantageous if the external distribution unit is located in the programming unit on which the programming tool that is used to create the project data runs. This allows the project data to be transferred directly from the programming unit to the safety controller. On the one hand, this is not very complex. On the other hand, this increases the fail-safe safety of the safety controller, since potential sources of error with regard to the transfer of the project data are excluded. A further advantage of this embodiment is that after the project data has been completed in a so-called trial operation, in which the functionality of the safety controller and the system to be controlled is tested and in which it is determined that changes to the project data are to be made, these in can be updated easily.

The project data is transferred from the programming unit to the safety controller, for example, using a cable. Advantageously, the programming unit is not permanently connected to the safety controller, but only temporarily. For example, for the period of programming, i.e. for the period in which the project data is generated. Or even only for the period during which the project data is being transferred from the programming unit to the safety controller. The programming unit can be understood as part of the safety control, since the project data, in particular the user program for the system to be controlled, are generated with the programming unit.

In a further embodiment of the invention, the control hardware components are control units and / or sensors and / or actuators.

Thus, not only the memories present in control units can be used as project data memories, but also the memories present in so-called intelligent sensors and intelligent actuators. This enables a particularly flexible distribution of the project data, in particular to the effect that partial processing of the project data can take place directly on site. This helps to improve the response time of the safety controller.

In a further embodiment of the invention, the project data are divided into a multiplicity of data packets, the individual data packets each being assigned to at least one of the project data memories.

This measure has the advantage that the project data can be specifically assigned to individual project data memories in accordance with a specific distribution criterion. In this way, a safety controller can be optimized with regard to different parameters by appropriate selection of the distribution criterion.

In a further embodiment of the invention, a programming unit is provided for creating the project data, the programming unit being designed to generate assignment data, the distribution unit also being designed to distribute the project data to the project data memory as a function of the assignment data.

This measure has the advantage that the project data can be distributed to the individual project data memories according to a freely definable distribution criterion. At the same time, an error-free and, if necessary, as often reproducible distribution of the project data is guaranteed. As far as the binding nature of the assignment data is concerned, different approaches are conceivable. For example, the assignment data can have the character of a proposal and represent a list of preferences which, for example, the creator of the project data or the operator of the system to be controlled can change. On the other hand, it can also be provided that the assignment data cannot be changed, so that in this case the project data is distributed completely automatically.

The assignment data can contain, for example, the following information: For each project data memory contained in the safety controller, the data packets to be saved on this or the data packets then saved on it are listed. It is therefore clear which data packet belongs to which control hardware component or which data processing unit. The assignment data can also determine the order of the project data memories in which they are used when distributing the Project data are taken into account. Such an order provides that the project data memory that is used as the distribution unit is always taken into account first. For each individual project data memory, the assignment data can contain information about which data packets are to be stored in the respective project data memory or are then stored there. In addition, information can be provided for each control hardware component which specifies the project data memories on which the project data of the respective control hardware component are located. This information is required, for example, when booting or reconfiguring the safety controller. If this information is available, each control hardware component or each data processing unit can call up the project data provided for them from the corresponding project data memories in which they are stored. It is also conceivable to only generate part of the assignment data during the distribution process itself. This is useful, for example, for the data, specifying the project data memories on which the project data of the respective control hardware components are located.

In a further embodiment of the invention, the programming unit is designed to determine the assignment data as a function of at least one data processing parameter.

The data processing parameter represents a parameter relevant for data processing of a component used in data processing. This can be, for example, the clock frequency of a microprocessor, the data rates of a data broker or an event broker or a data bus interface or the storage capacity of a project data memory. If data processing parameters of the control hardware components or individual units built into them are taken into account when determining the assignment data, then the project data can be distributed from the point of view of optimized data processing. For example, project data that requires high computing power to process can be stored in control hardware components that are equipped with a powerful microprocessor. In addition, depending on their size, data packets can be based on those in the safety controller Data storage are distributed. For example, small data packets can be stored in a targeted manner in data memories with a small storage capacity. This measure is particularly advantageous for a completely automatic distribution of the project data to the project data memory.

In a further embodiment of the invention, the programming unit is designed to determine the assignment data as a function of at least one function assignment variable.

The function allocation variable represents for an individual data packet or a group of data packets that project data memory in which this data packet or this group is to be stored. The project data memory is defined in that the storage is to take place in that project data memory which is located in that control hardware component, in particular that control unit, in which the project data are processed. For example, due to the spatial proximity of a sensor, the signals of which are required as input signals, and / or the spatial proximity of an actuator that is controlled by the determined control signals. This measure enables a short reaction time of the safety controller, since the project data is kept on site and thus the data exchange between the individual control hardware components is reduced to a minimum. The function assignment variables are advantageously specified by the programmer of a user program in that he stipulates which scopes of the user program should run on soft control hardware components, for example control units.

In a further embodiment of the invention, at least part of the project data is stored redundantly in the project data memory.

The redundant storage of the data packets is achieved by duplicating the respective data packets. The duplicated data packets are then distributed independently to the project data memories, with the proviso that the original and the duplicated data packets are each in a different project data memory get saved. This measure has the advantage that the availability of the safety control and thus of the controlled system is increased. If, for example, a non-safety-relevant control hardware component fails, the project data that were stored in your project data memory are still available because they are still available in another project data memory. This also makes it easier to replace a defective control hardware component. All you have to do is replace the defective component with a new component. The project data required for the new component can, for example, be automatically requested from the respective project data memories on which they are still stored and stored in the project data memory of the new component. The redundant storage of the project data also enables individual control tasks to be carried out in parallel.

In a further embodiment of the invention, at least some of the project data memories are designed to store the project data supplied in each case in a non-volatile manner.

This measure has the advantage that the project data is still available, for example after a power failure or after the safety controller has been switched off. This increases the availability of the safety controller. The safety controller does not need to be re-initialized. For example, memory cards in the form of SD cards or CF cards are used for this, or flash memories are used.

The progress of the distribution process can preferably be displayed by graphic means during the distribution of the project data to the individual project data stores. In this way, for example, an operator of the system to be controlled can easily find out about the status of the distribution process.

Each control hardware component preferably contains a project data memory. This enables an optimal distribution of the project data. The project data is available wherever it is needed.

The application running on the system to be controlled can also be referred to as a process, which includes both standard control tasks and safety control tasks.

Fig. 1

eine schematische Darstellung einer zu steuernden Anlage;

Fig. 2

eine schematische Darstellung von an einer Anlagenhardwarekomponente angeordneten Steuerungshardwarekomponenten;

Fig. 3

eine vereinfachte Darstellung von in der neuen Sicherheitssteuerung vorhandenen Projektdatenspeichern;

Fig. 4

eine vereinfachte Darstellung einer grafischen Oberfläche für das Erstellen von Projektdaten;

Fig. 5

ein vereinfachtes Flussdiagramm zur Erläuterung des neuen Verfahrens; und

Fig. 6

ein vereinfachtes Flussdiagramm zur Erläuterung der Bereitstellung von Projektdaten.

Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

Fig. 1

a schematic representation of a system to be controlled;

Fig. 2

a schematic representation of control hardware components arranged on a system hardware component;

Fig. 3

a simplified representation of the project data memories available in the new safety controller;

Fig. 4

a simplified representation of a graphical user interface for creating project data;

Fig. 5

a simplified flow chart to explain the new method; and

Fig. 6

a simplified flow chart to explain the provision of project data.

In Fig. 1 a system to be controlled is designated in its entirety with the reference number 10.

The system 10 consists of a large number of system hardware components 12. In the present exemplary embodiment, there is a loading station 14, a processing station 16, a test station 18, a conveyor unit 20 and a packaging and palletizing station 22. Furthermore, there is a safety controller in its entirety denoted by the reference number 24. The safety controller 24 contains a large number of control hardware components 26. The control hardware components 26 are control units 28, sensors 30 and actuators 32. The individual control units 28, sensors 30 and individual actuators 32 are each assigned to one of the system hardware components 12 and are spatially arranged there . The control hardware components 12 are connected to one another via a connection unit 34. The connection unit 34 is a data bus which is designed, for example, as an Ethernet-based field bus. A data bus system is preferably used, which works according to the SafetyNET p ® communication model, which can be traced back to the applicant.

With the loading station 14, the processing station 16 is filled with workpieces. These workpieces are processed in the processing station 16. The machined workpieces are then passed on from the machining station 16 to the test station 18, in which it is checked whether the machined workpiece meets the corresponding test criteria. If these test criteria are met, the processing station 16 can be filled again with a new workpiece. The processed workpiece is transferred to the packaging and palletizing station 22 by means of the conveyor unit 20. In this, several processed workpieces are combined into bundles, which are then stacked on a pallet.

The working areas of the individual stations 14, 16, 18, 22 can be secured, for example, by protective doors that are equipped with safety switches, by means of which a tumbler with locking can be implemented. Alternatively or in addition, light grids or light curtains can also be used. In addition, the individual stations 14, 16, 18, 22 can be provided with emergency stop buttons with which the respective station can be switched to a safe state by disconnecting it from the power supply. Contactors are controlled accordingly for this. The aforementioned protective doors, light grids, light curtains and emergency stop buttons are safety-relevant sensors that are contained in the sensors 30. The contactors are safety-relevant actuators that are contained in the actuators 32. The sensors 30 can furthermore comprise non-safety-relevant sensors. These are sensors that record operating variables, for example input variables required for drive or position control, such as rotational speeds, angles or speeds. The actuators 32 can also include actuators that are not relevant to safety. These can be motors or actuating cylinders, for example.

In the present exemplary embodiment, a control unit 28 is assigned to each station 14, 16, 18, 22. For this purpose, the control units 28 are structurally independent Components trained. This also applies to the sensors 30 and the actuators 32. However, this is not intended to have a restrictive effect. It is also conceivable, for example, to assign a common control unit to two stations. The individual system hardware components can be structurally and spatially separated from one another. However, it is also conceivable that some of these components are operatively connected to one another.

In Fig. 1 Functionally identical components are provided with the same reference number, the use of dashes indicating that the individual components with the same reference number can be designed differently due to the individual assignment to individual system hardware components. The same applies to signals. This form of identification also applies to the other figures.

In Fig. 2 the processing station 16 and the control hardware components assigned to it are shown in a more detailed representation. These are the control unit 28 ', the sensors 30' and the actuators 32 ', which are connected to one another by the connection unit 34.

The control unit 28 'has a two-channel redundant structure in order to achieve the necessary fail-safe security for controlling safety-critical applications or processes. Representing the two-channel structure are in Fig. 2 two separate processors, namely a first processor 40 and a second processor 42, shown. The two processors 40, 42 are connected to one another via a bidirectional communication interface 44 in order to be able to monitor one another and exchange data. The two channels of the control unit 28 'and the two processors 40, 42 are preferably constructed diversely, ie different from one another, in order to largely rule out systematic errors.

Reference numeral 46 denotes an input / output unit which is connected to each of the two processors 40, 42. The input / output unit 46 takes Control input signals 48 from the sensors 30 ′ and forwards them in an adapted data format to each of the two processors 40, 42. In addition, the input / output unit 46 generates control output signals 50 as a function of the processors 40, 42, with which the actuators 32 ′ are controlled.

The reference number 52 denotes a project data memory in which project data 54 are stored in the form of data packets. This is a first data packet 56 which contains first configuration data 58 for a data broker 60. The project data memory 52 contains a second data packet 62 with second configuration data 64 for an event broker 66. The project data memory 52 contains a third data packet 68 with third configuration data 70 for a data bus interface 72 contains itself. In addition, the project data memory 52 contains a fifth data packet 76 and a sixth data packet 78. These two data packets contain program data which represent the scope of a user program that is processed in the control unit 28 '. The project data memory 52 also contains a seventh data packet 80 which contains parameterization data. These parameterization data are required, for example, when processing the project data and define, for example, value ranges for variables or functionalities.

The actuators 32 'and the sensors 30' are also equipped with project data memories 52 ', 52 ", 52"', 52 "". This is not intended to have a restrictive effect. Not all control hardware components need to have project data memories. that only project data 54, which are processed in units contained in the control unit 28 ', are stored in the project data memory 52. Project data 54 that are required or processed in another control hardware component can also be stored in the project data memory 52 Data packets from units that are contained in the control unit 28 'are also stored in a project data memory of another control hardware component Fig. 2 The selected division into the individual data packets is not restrictive Have an effect. It is also conceivable to combine different project data, all of which are intended for a data processing unit, for example program data and configuration data, into a data packet.

The project data memory 52 is designed such that the project data 54 stored in it are stored non-volatile. For this purpose, the project data memory 52 is designed, for example, as a flash memory or as an SD card or as a CF card.

The project data memory 52, the data broker 60, the event broker 66 and the data bus interface 72 are data processing units. The data bus interface 72 ensures that a data exchange between the control unit 28 'and the connection unit 34 is synchronized, i.e. takes place in accordance with the protocol of the data bus system used. The data bus interface 72 controls both the data broker 60 and the event broker 66. Event-based data is exchanged between the control unit 28 'and the connection unit 34 and thus another control hardware component via the event broker 66. For example, the project data to be stored in the project data memory 52 are supplied via the event broker 66 during the distribution process. Furthermore, project data which it has requested and which are stored in the project data memory 52 can be fed to another control hardware component via the event broker 66.

A data-based data exchange takes place via the data broker 60 between the control unit 28 'and the connection unit 34 and thus one of the other control hardware components. For example, control input signals required in control unit 28 'are supplied via data broker 60 or control output signals generated in control unit 28' are output.

The project data 54 are in the form of machine code. For fail-safe operation of the control unit 28 ', two data packets 76, 78 with program data are stored in the project data memory 52. The fifth data packet 76 is for the first Processor 40 and the sixth data packet 78 for the second processor 42 is determined. The fifth data packet 76 comprises a first security code 82 and a standard code 84. The first security code 82 comprises those control instructions which are to be processed by the first processor 40 as part of the security tasks to be carried out by the control unit 28 '. These types of control instructions are hereinafter referred to as safety control instructions. The standard code 84 comprises those control instructions which are to be processed by the first processor 40 as part of the standard tasks to be performed by the control unit 28 '. Standard tasks are tasks that result from the desired "normal" operational sequence of the plant and that have no particular safety-related significance. These types of control instructions are hereinafter referred to as standard control instructions. The sixth data packet 78 includes a second security code 86, which includes those control instructions that are to be processed by the second processor 42. These control instructions are hereinafter referred to as safety control instructions.

Depending on the progress of processing, on the one hand a first current safety control instruction 88 and on the other hand a current standard control instruction 90 are processed in the first processor 40. A second current safety control instruction 92 is processed essentially at the same time in the second processor 42.

During the processing of the current standard control instruction 90, which is a non-safety-relevant control instruction, first non-safety-relevant data 94 are exchanged between the first processor 40 and the input / output unit 46. Here, instantaneous values of non-safety-relevant control input signals 48, which are generated by non-safety-relevant sensors 95, are fed to the first processor 40. The non-safety-relevant sensors 95 are sensors which, for example, detect input variables required for drive control. This can be, for example, speeds, angles or speeds. The non-safety-relevant sensors 95 are designed to be non-fail-safe. The input / output unit 46 instantaneous values of non-safety-relevant control output signals 50 are supplied, which non-safety-relevant actuators 97 are supplied to control them. The non-safety-relevant actuators 97 can be motors or actuating cylinders, for example. The instantaneous values of the non-safety-relevant control output signals 50 are determined as a function of the non-safety-relevant control input signals 48 in accordance with the standard control instructions. In this case, it may be necessary to determine intermediate variables, the instantaneous values of which are fed to a main memory 98 by means of second non-safety-relevant data 96 and are temporarily stored there.

As part of the processing of the first current safety control instruction 88, which is a safety-relevant control instruction, first safety-relevant data 100 are exchanged between the first processor 40 and the input / output unit 46. Here, instantaneous values of safety-relevant control input signals 48 ′, which are generated by safety-relevant sensors 101, are fed to the first processor 40. The safety-relevant sensors 101 are, for example, emergency stop buttons, protective doors, speed monitoring devices or other sensors for recording safety-relevant parameters. The input / output unit 46 is supplied with instantaneous values of safety-relevant control output signals 50 ', which safety-relevant actuators 103 are supplied to control them. The safety-relevant actuators 103 are, for example, redundant safety contactors with working contacts which are arranged in the connection between a power supply 102 and the processing station 16. The power supply 102 of the processing station 16 can thus be switched off in two channels, which makes it possible to transfer at least the processing station 16 to a safe state if a corresponding malfunction occurs. The instantaneous values of the safety-relevant control output signals 50 'are determined as a function of the safety-relevant control input signals 48' in accordance with the safety control instructions. It may be necessary to determine safety-relevant intermediate values, the instantaneous values of which are fed to the main memory 98 by means of second safety-relevant data 104 and are temporarily stored there.

In the course of processing the second current safety control instruction 92, which is a safety-relevant control instruction, the procedure is in accordance with the first current safety control instruction 88. With regard to the second current safety control instruction 92, third safety-related data 106, which correspond to the first safety-related data 100, and fourth safety-related data 108, which correspond to the second safety-related data 104, are used in a corresponding manner.

The reference numeral 110 identifies project data that may be exchanged between individual control hardware components and thus project data memories 52, 52 ', 52 ", 52"', 52 "".

In the Fig. 2 The selected representation, according to which both non-safety-relevant control instructions and safety-relevant control instructions are processed in the control unit 28 ', should not have a restrictive effect. It is also conceivable that the control unit 28 'is designed for the exclusive processing of safety-relevant control instructions.

In Fig. 3 are the project data memories 52 contained in the control units 28, the project data memories 52 'contained in the safety-relevant actuators 103, the project data memories 52 "contained in the non-safety-relevant actuators 97, the project data memories 52''' contained in the non-safety-relevant sensors 95 and the project data memories 52 "" contained in the safety-relevant sensors 101. The individual project data memories are connected to one another via the connection unit 34. The entirety of the project data memories together form a virtual project memory 120 may be present between individual project data memories and the connection unit 34 are omitted.

In Fig. 3 a programming unit is designated in its entirety with the reference numeral 122. The programming unit 122 essentially consists of a computer 124 which is connected to a display unit 126. A computer program 128 is executed on the computer 124. The computer program 128 enables the creation of project data 130 which represent an application running on the system to be controlled. The project data 130 include program data, configuration data and parameterization data. The computer program 128 is often referred to in technical terminology as a programming tool. The computer 124 can be designed as a PC and the display unit 126 as a monitor.

According to one aspect of the invention, the project data 130 generated with the programming unit 122 and present on the computer 124 are transferred to the project data memories 52, 52 ′, 52 ″, 52 ″ ″, 52 ″ ″ of a distributed safety control 24 130 divided into a plurality of data packets 132, the individual data packets 132 each being assigned to one of the project data memories 52, 52 ', 52 ", 52"', 52 "" '. The project data, more precisely the individual data packets 132, are distributed to the individual project data memories as a function of assignment data 134. The assignment data 134 are generated in the programming unit 122. The assignment data 134 can be determined, for example, as a function of at least one data processing parameter or as a function of at least one function assignment variable.

In order to be able to distribute the project data 130 to the individual project data memories 52, they are fed to a distribution unit. According to the invention, three different approaches are possible here. A safety controller 24 can be designed in such a way that a programmer can choose one of these three procedures at will. But it is also conceivable that a safety controller 24 is designed such that only one or two of the procedures for the transfer of the project data 130 are provided.

A first procedure is indicated by a sequence of arrows 136. In this case, both the project data 130 and the assignment data 134 are transmitted, for example in a wired manner, from the programming unit 122 via a first interface 138 provided for this purpose to the project data memory 52, which is located in the control unit 28. In this case, the distribution unit is a project data memory arranged in the safety controller. The project data memory 52 arranged in the control unit 28 distributes the data packets 132 according to the assignment data 134 to the individual project data memories 52, 52 ', 52 ", 52"', 52 "" 'contained in the safety controller 24. Said project data memory 52 is for this purpose designed to be able to forward project data supplied to it to at least one other project data memory.

A second procedure is shown by a first arrow sequence 140. In this case, the project data 130 and the assignment data 134 are first made available on an external distribution unit 142 contained in the computer 124. The functionality of the external distribution unit 142 corresponds to the project data memory 52 contained in the control unit 28. The project data 130 are then supplied to the connection unit 34 in a wired manner via a second interface 144 provided for this purpose and, according to the assignment data 134, to the individual project data memories contained in the safety controller 24 52, 52 ', 52 ", 52"', 52 "" '. The external distribution unit 142 does not have to be permanently connected to the safety controller 24. It is sufficient if this is only connected for the period of data transmission, for example.

A third procedure is indicated by a second sequence of arrows 146. In this case, both the project data 130 and the assignment data 134 are transferred to a mobile storage medium 148. The mobile storage medium 148 can be, for example, an SD card, a CF card or a USB stick. The mobile storage medium 148 is then stored in a Receiving unit 150 introduced. The project data 130 are then fed to the project data memory 52 contained in the control unit 28, which then distributes the data packets 132 according to the assignment data 134 to the project data memories 52, 52 ', 52 ", 52"', 52 "contained in the safety controller 24. '' takes over.

As far as the distribution of the project data 130 to the individual project data memories 52, 52 ', 52 ", 52"', 52 "" is concerned, different approaches are conceivable for this they are processed, stored in. This is in Fig. 3 shown as follows: The control unit 28 ″ contains a first data processing unit 152. The project data required by the first data processing unit 152 are stored in the form of a data packet 132 ′ in the project data memory 52, which is contained in the control unit 28 ″. The first data processing unit 152 can thus call up the project data it needs directly from this project data memory. In this approach, the assignment data 134 are determined as a function of at least one function assignment variable. With this approach, the project data 130 are stored in the control hardware component in which they are processed.

According to a second approach, the assignment data 134 are determined as a function of at least one data processing parameter. The data processing parameter can be, for example, the clock frequency of one of the two processors 40, 42 or the data rate of the data broker 60 or the event broker 66 or the storage capacity of a project data memory 52, 52 ', 52 ", 52"', 52 " In some exemplary embodiments, the characteristic variable is automatically determined by the distribution unit in that the distribution unit queries the project data memory connected to the connection unit.

In the second approach, the project data 130 are preferably distributed in such a way that they are stored in control hardware components that have a high data processing capacity. With this approach, the project data 130 essentially arbitrarily, ie distributed without function assignment to the project data memories 52, 52 ', 52 ", 52"', 52 ""'present in a safety controller 24. In Fig. 3 This is shown as follows: The project data required by a second data processing unit 154 are stored in the form of the data packet 132 ″ in the project data memory 52, which is contained in the control unit 28 '. In this case, the project data are thus stored in the control unit in which They are also processed of a data packet 132 "" is stored in one of the project data memories 52 ". The third data processing unit 156 can then access this project data via the project data memory 52 which is contained in the control unit 28 ′. For the third data processing unit 156 it appears as if the project data required by it are stored virtually on the project data memory 52 which is contained in the control unit 28 '. This is in Fig. 3 for the third data processing unit 156, the project data memory 52, which is contained in the control unit 28 ', has the function of a proxy. In order to enable any distribution of the project data to the individual project data memories, at least some of the project data memories are designed to automatically forward project data to other project data memories and to request project data from other project data memories. It is conceivable that individual project data memories have both functionalities at the same time With this approach, it is also conceivable to save a minimum amount of project data on the individual project data memories, for example the project data required for booting the safety controller are required for this in the respective control hardware component or data processing unit.

In order to increase the availability of the safety controller 24, at least some of the project data 130 are stored redundantly in the project data memories 52, 52 ', 52 ", 52''', 52 '''' saved. This is in Fig. 3 The project data required by a fourth data processing unit 158 are stored in the form of a data packet 132 '''' both on the project data memory 52, which is contained in the control unit 28 ', and on one of the project data memories 52''''. As described in connection with the third data processing unit 156, the project data of the fourth data processing unit 158 are not stored on the project data memory 52, which is contained in the control unit 28 '''. Rather, the fourth data processing unit 158 can either access the data packet 132 ''', which is stored on the project data memory 52 contained in the control unit 28', or on the data packet 132 '''' which is stored in one of the project data memories 52 '''' is saved. If, for example, the project data memory 52 '''' on which the data package 132 '''' is stored, or even the complete control hardware component in which this project data memory is contained, fails, the project data required by the fourth data processing unit 158 are still available , in this case on the project data memory 52, which is contained in the control unit 28 '. Project data that are primarily stored in the project data memory that is contained in the control unit in which the project data are processed can also be stored redundantly. This applies, for example, to the project data of the data package 132 '.

In the Fig. 3 The representation chosen is not intended to have a restrictive effect. Safety controls can be designed differently. For example, a safety control can be used in which the non-safety-relevant sensors, the safety-relevant sensors, the non-safety-relevant actuators, the safety-relevant actuators and the control units are each equipped with project data memories, as described in Fig. 3 is shown. However, safety controls can also be used in which, for example, only the control units are equipped with project data memories. However, it is also conceivable to use safety controls that have a degree of equipment with project data memories that lies between these two examples. In addition to the control units, the safety-relevant sensors and the safety-relevant actuators are preferably also equipped with data memories. Furthermore is it is not absolutely necessary for both the first interface 138 and the receiving unit 150 to be arranged in a control unit. Both can be arranged individually or together in any control hardware component. It is also conceivable that the interface 138 and / or the recording unit 150 form a structural unit together with one of the project data memories. Furthermore, it can also be provided that more than one of the project data memories built into the safety controller can be used as a distribution unit. In addition, the selected representation, in which only one of the project data memories 52 ', 52 ", 52"', 52 "'', namely the one contained in the top drawing level contains a data packet, should not have any restrictive effect. For reasons For the sake of clarity, data packages have not been shown for the project data memories contained in the drawing levels below.

In Fig. 4 a graphical user interface is designated in its entirety with the reference numeral 170. This graphical surface enables a programmer to create the project data 130. Overall, program data, configuration data and parameterization data are created.

The graphical user interface 170 includes a system software component field 172 which contains a multiplicity of predefined system software components 174 in the form of graphic symbols. The user program and thus the program data are created by providing a large number of system software components. For this purpose, the graphical user interface 170 contains a first component field 176. The system software components to be provided are selected and transferred to the first component field 176, as indicated by an arrow 178. The first component field 176 thus contains a multiplicity of provided system software components 180. A component part program is created by logically linking the provided system software components 180. For this purpose, logic inputs and logic outputs of these system software components are connected to one another, which is represented by a large number of connections 182. In addition to the selection of predefined system software components, new system software components be created, as indicated by the new system software component 184. The individual system software components can be so-called elementary components which themselves do not contain any further software components. However, it can also be a matter of so-called group components, which themselves contain further software components. An elementary component contains several aspect blocks. Each of these aspect blocks is assigned to one of several different control aspects, each of these control aspects representing an independent sub-aspect of the safety control. The system software component contains all those aspect blocks that are important for the system hardware component that the system software component represents. Compared to an elementary component, a group component contains not only the aspect blocks but also software components that can be designed as elementary or group components. By using group components, a user program with several hierarchical levels can be created.

The different control aspects can advantageously be the following control aspects: standard control aspect, safety control aspect, diagnosis aspect, visualization aspect, entry control aspect, cooling aspect, access authorization aspect, maintenance aspect, locking aspect, manual operation aspect or data management aspect.

For each aspect block contained in a system software component, there are at least those logic variables and / or those parameters and / or those sensor signals that are required for processing and are to be fed to the aspect block via associated inputs, and those logic variables and / or those parameters and / or those output signals which are each determined in the number of aspect blocks and output from the aspect block via associated outputs, initially determined according to their reason. The definition of the specific sensors and / or actuators that are to be connected to the respective aspect block is ultimately only carried out when the user program is created. Furthermore, at least some of the aspect blocks contained in a system software component are present a function program is stored in each case, which defines the aspect properties of the system hardware components for the control aspect to which the respective aspect block is assigned.

The graphical user interface 170 furthermore contains an aspect field 186. A multiplicity of aspect blocks 188 are arranged in this aspect field 186. Each of these aspect blocks is assigned to the same control aspect. The multiplicity of aspect blocks 188 includes the aspect blocks contained in all hierarchical levels of the user program.

The graphical user interface 170 further includes a sensor field 190. A multiplicity of graphical sensor symbols 192 are arranged in this sensor field 190. A graphic sensor symbol is provided for each sensor contained in the system to be controlled. The graphic surface 170 contains an actuator field 194 as a further field. A multiplicity of graphic actuator symbols 196 are arranged in this actuator field 194. A graphic actuator symbol is provided for each actuator contained in the system to be controlled. An aspect subprogram is created for the multiplicity of aspect blocks 188 contained in the aspect field 186. For this purpose, what is known as I / O mapping is carried out for at least some of the aspect blocks both for their inputs and for their outputs. This means that at least some of the signal inputs are assigned those sensors whose sensor signals are processed in the respective aspect block. This is shown by way of example by an arrow 198. In addition, at least some of the control outputs are assigned actuators that are controlled with the output signals determined in the respective aspect block. This is indicated by an arrow 200 by way of example. Alternatively, the I / O mapping can also be carried out by means of textual entries in an input field 202.

The graphical user interface 170 contains a control software component field 204 which contains a multiplicity of predefined control software components 206. Each of these control software components 206 represents a control hardware component that is contained in a distributed safety controller 24 can be used. The control hardware components are, for example, control units, sensors or actuators.

The graphical user interface 170 also contains a second component field 208. In this second component field 208, the programmer of the user program can insert those control software components that represent those control hardware components from which the distributed safety controller 24 is constructed. This is done by selecting individual control software components 206 and transferring them to the second component field 208, as indicated by an arrow 210 by way of example. The second component field 208 thus contains a large number of provided control software components 212 Assign system software components 180 to the provided control software components 212. This is indicated by arrows 214, 216. Function allocation variables are generated from these allocations, and the allocation data 134 are then determined as a function of these. When determining the function assignment variables, the connections 182 between the individual system software components 180 can also be taken into account. Furthermore, the I / O mapping carried out for the aspect blocks can also be taken into account.

The assignment data 134 can, however, also be determined automatically, that is to say without the programmer making an assignment. For each control hardware component 26 represented by a control software component 212, at least one data processing parameter is stored in a database so that the assignment data 134 can be determined, for example, as a function of these data processing parameters. In this case, the project data 130 is distributed to the individual project data memories from the point of view of the data processing capacity of the individual control hardware components. The following procedure is also conceivable: the programming tool is designed so that the programming unit first sends inquiries to the individual control hardware components before the start of the distribution process in order to determine the respective current data processing parameters.

With regard to the determination of the assignment data 134, various configurations are conceivable: In a first configuration, the assignment data 134 are determined exclusively as a function of data processing parameters. In this case, the project data are distributed according to the data processing capacity of the individual control hardware components. In a second embodiment, the assignment data 134 are determined exclusively as a function of function assignment variables. The function assignment variables represent those assignments that the programmer prescribes by assigning individual system software components to individual control software components. In this case, the programmer defines the distribution of the project data to the individual project data memories. The function allocation variables represent a storage location, in particular a project data memory, which is defined by the proximity of project data to be processed and the data required for this, which originate, for example, from a sensor or another control unit. In a third embodiment, the assignment data 134 can be determined both as a function of data processing parameters and as a function of function assignment parameters. In this case, it is conceivable that, using the data processing parameters, a proposal is first made for the assignment of the project data 130 to the individual project data memories, which the programmer can then still change according to his ideas. This is a two-step process. First of all, a distribution of the project data according to the aspect of the data processing capacity is proposed, which can then be modified based on the aspect of the function assignment.

For the predefined control software components 206, predefined configuration data can also be stored in a database. Thus, the project data 130 is automatically included by providing control software components also the associated configuration data. However, there is also the possibility of changing configuration data when creating the user program or of specifying them at all, for example by making appropriate entries in the input field 202. This can also be done, for example, after the user program has been created. For the aspect blocks 188, parameterization data can be stored in a database in a corresponding manner. In addition, as in the case of the configuration data, there is also the possibility of changing these or of specifying them at all.

This in Fig. 5 The flowchart shown shows the sequence of the new method.

According to a step 230, the project data 130 are provided. In a subsequent step 232, the data packets 132 are generated. This is followed by a step 234 in which the assignment data 134 are generated. In a step 236, the individual data packets 132 are then distributed to the individual project data memories 52, 52 ', 52 ", 52"', 52 "" according to the assignment data 134. Depending on the procedure used to distribute the data packets, this closes step 236 does not go directly to step 234. If the data packets are distributed using a mobile storage medium 148, a step 238 is carried out between step 234 and step 236 in which the data packets 132 and the assignment data 134 are stored on the mobile storage medium 148 can be saved.

This in Fig. 6 The flowchart shown shows the basic procedure when providing the project data 130.

In a step 240, system software components 180 are provided. In a subsequent step 242, the provided system software components 180 are linked. This is followed by a step 244 in which the sensors and actuators are specified for the individual aspect blocks 188, ie what is known as I / O mapping is carried out. In a subsequent step Control software components 212 are provided 246. In a subsequent step 248, the system software components 180 provided are assigned to the control software components 212 provided.

Claims (12)

1. A safety controller for controlling an automated installation (10) on the basis of project data (130), wherein the project data (130) represent an application running on the installation (10), comprising

   a plurality of controller hardware components (28, 28', 28", 28'''), each comprising a respective project data memory (52, 52', 52", 52''', 52'''') and at least one data processing unit (152, 154, 156, 158), with the project data memories (52, 52', 52", 52''', 52'''') each being designed for storing project data (130, 132) supplied to them,

   a connecting unit (34) via which the controller hardware components (28, 28', 28", 28''') are connected to one another, and

   a distribution unit (52, 142) designed for distributing at least some of the project data (130, 132) to at least some of the project data memories (52, 52', 52", 52''', 52'''') via the connecting unit (34),

   wherein project data (132") intended for a first data processing unit (154) are stored in a first project data memory (52) located in the controller hardware component (28') where the first data processing unit (154) is arranged, and

   wherein project data (132''') required for a second data processing unit (156), which is also located in the controller hardware component (28'), are stored in a second project data memory (52"),

   characterized in that the project data (130, 132) comprise one or more of program data (76, 78), configuration data (58, 64, 70) or parameterization data (80), wherein the program data represent an application program, the configuration data represent a cycle time and the parameterization data represent value ranges for individual variables or functionalities used in the user program,

   that the first project data memory (52) is designed for forwarding project data supplied to it to at least one other project data memory (52', 52''', 52'''') or for requesting project data stored in another project data memory (52', 52''', 52''''), and that the second project data memory (52") is located in another controller hardware component, wherein the second data processing unit (156) can access the project data (132''') in the second project data memory (52") via the first project data memory (52).
2. The safety controller of claim 1, characterized in that the distribution unit (52, 142) is one of the project data memories (52).
3. The safety controller of one of the preceding claims, characterized in that the distribution unit (52, 142) is an external distribution unit (142) which is connected at least temporarily to an interface (144) provided for this purpose in the safety controller (24).
4. The safety controller of one of the preceding claims, characterized in that the controller hardware components (26) are control units (28) and/or sensors (30) and/or actuators (32).
5. The safety controller of one of the preceding claims, characterized in that the project data (130) are divided into a plurality of data packets (132), wherein the individual data packets (132) each are allocated to at least one of the project data memories (52, 52', 52", 52''', 52'''').
6. The safety controller of one of the preceding claims, characterized in that a programming unit (122) is provided for generating the project data (130, 132), wherein the programming unit (122) is designed for generating allocation data (134), wherein the distribution unit (52, 142) is designed for distributing the project data (130) on the basis of the allocation data (134) to the project data memories (52, 52', 52", 52''', 52'''').
7. The safety controller of claim 6, characterized in that the programming unit (122) is designed for determining the allocation data (134) on the basis of at least one data processing characteristic figure.
8. The safety controller of claim 6 or 7, characterized in that the programming unit (122) is designed for determining the allocation data (134) on the basis of at least one function allocation quantity.
9. The safety controller of one of the preceding claims, characterized in that at least part of the project data (130, 132) is stored redundantly in the project data memories (52, 52', 52", 52''', 52'''').
10. The safety controller of one of the preceding claims, characterized in that at least some of the project data memories (52, 52', 52", 52''', 52'''') are designed for storing the respectively supplied project data (130) in a zero-voltage-proof manner.
11. A method for controlling an automated installation (10) using a safety controller (24) on the basis of project data (130), which represent an application running on the installation (10), wherein the safety controller (24) comprises a plurality of controller hardware components (26) which are connected to one another via a connecting unit (34), wherein at least some of the controller hardware components (26) comprise a respective project data memory (52, 52', 52", 52''', 52'''') and at least one data processing unit (152, 154, 156, 158), and wherein the project data memories (52, 52', 52", 52''', 52'''') each are designed for storing project data (130) supplied to them, the method comprising the steps of

    - providing project data (130, 132), and

    - distributing at least some of the project data (130, 132) to at least some of the project data memories (52, 52', 52", 52''', 52''''),

    wherein project data (132") intended for a first data processing unit (154) are stored in a first project data memory (52) located in the controller hardware component (28') where the first data processing unit (154) is arranged, and

    wherein project data (132''') required for a second data processing unit (156), which is also located in the controller hardware component (28'), are stored in a second project data memory (52"),

    characterized in that the project data (130, 132) comprise one or more of program data (76, 78), configuration data (58, 64, 70) or parameterization data (80), wherein the program data represent an application program, the configuration data represent a cycle time and the parameterization data represent value ranges for individual variables or functionalities used in the user program, that the first project data memory (52) is designed for forwarding project data supplied to it to at least one other project data memory (52', 52''', 52'''') or for requesting project data stored in another project data memory (52', 52''', 52''''), and that the second project data memory (52") is located in another controller hardware component, wherein the second data processing unit (156) accesses the project data (132'"') in the second project data memory (52") via the first project data memory (52).
12. A computer program product comprising a data carrier with program code, which is designed for performing a method of claim 11 when the program code is executed on a safety controller (24) of one of claims 1 to 10.

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